I'm seeing this sort of question crop up on a lot of Apple/iPod Touch forums:
"Should I get an iPod Touch now, or wait until July 11/September?"
"Should I go for an 8GB Touch or a 16GB Touch?"
It's generally always based on the current price of the bottom and middle-ranged drive size - never the 32GB one.
It would be fascinating to hear Apple's marketing perspective on it.
The basic iPod Touch is $299 for 8GB, and the new 3G iPhone will be an up-front cost of $199 (yes, we know you'll be paying more than that in subscription fees - but it all depends on how you view it etc. etc.). No matter what way you look at it, you're getting the same product (well, the 8GB iPhone is better than the 8GB iPod Touch in numerous ways) for $100 fewer. It simply doesn't make sense from a marketing perspective for the Touch.
Also, you can pick up an 8GB Nano for $199 - much cheaper than the 8GB Touch - and despite the multi-touch features and other enhanced capabilities of the Touch, the 8GB Nano is a fine gadget with many plusses over the Touch in certain areas.
I could be wrong here, but as far as I can tell, Apple has traditionally offered a maximum of two capacity options for each iPod in the range, which makes it seem all the more odd that the Touch is available in three capacity options. It's the sort of consumer choice that causes people to dither and simply not make a purchase. (I don't want to invoke Godwin's Law here, but as Hitler said: "When you offer a child the choice of a piece of meat, an apple, or a cake, it's never the meat that he chooses. There's an ancestral instinct there.")
What is my point here?
Well, I have a strong suspicion the 8GB Touch will vanish as of 11 July and the 32GB option will come down by $100 to $399 - the 8GB chips will be used to bolster stock of the 3G iPhone.
I have no information to back this up, but it makes sense from a manufacturing and marketing position.
I'm holding off until 23 July to get my 32GB Touch; it'll give me the best chance of catching a price drop, and the 2.0 software update for free - but I'm not going to wait any longer than that, as I'll be back home in the UK, and I'm not prepared to pay almost $140 more for a 32GB Touch than my friends in the States.